Is it possible to translate new strings according to already translated ones?

A person translates from Englisg to Russian and some strings repeat themselves so instead of a lot of copy paste, he wants to re-translates the same strings in one click. All English strings that he already translated, will be automatically translated to his Russian translation.

If you open Dictionary Manager while editing translations in Translation Editor or SIL Editor then when you start editing new cell and there is already such translation in dictionary then it will be automatically inserted.
So you can just add translations in dictionary and then keep it open while editing translations. Or you can add all items to dictionary translate them there (dictionary skips identical items while adding).